- added ability for Tcl commands to have optional arguments with None value (meaning missing value). This case should be treated for each Tcl command in execute() method

tclCommands/TclCommand.py

@@ -177,19 +177,26 @@ class TclCommand(object):
         arguments = []
         n = len(args)
 
-        name = None
+        option_name = None
+
         for i in range(n):
             match = re.search(r'^-([a-zA-Z].*)', args[i])
             if match:
-                assert name is None
-                name = match.group(1)
+                # assert option_name is None
+                if option_name is not None:
+                    options[option_name] = None
+
+                option_name = match.group(1)
                 continue
 
-            if name is None:
+            if option_name is None:
                 arguments.append(args[i])
             else:
-                options[name] = args[i]
-                name = None
+                options[option_name] = args[i]
+                option_name = None
+
+        if option_name is not None:
+            options[option_name] = None
 
         return arguments, options
 
@@ -211,6 +218,7 @@ class TclCommand(object):
         for argument in arguments:
             if len(self.arg_names) > idx:
                 key, arg_type = arg_names_items[idx]
+
                 try:
                     named_args[key] = arg_type(argument)
                 except Exception as e:
@@ -226,7 +234,12 @@ class TclCommand(object):
                 self.raise_tcl_error('Unknown parameter: %s' % key)
             try:
                 if key != 'timeout':
-                    named_args[key] = self.option_types[key](options[key])
+                    # None options are allowed; if None then the defaults are used
+                    # - must be implemented in the Tcl commands
+                    if options[key] is not None:
+                        named_args[key] = self.option_types[key](options[key])
+                    else:
+                        named_args[key] = options[key]
                 else:
                     named_args[key] = int(options[key])
             except Exception as e: